Are you referring to
Multiply both sides by to get
Now, get those 2 terms including [tex]R_2[tex] alone on one side by subtracting and from both sides:
Finally divide both sides by
How would I go about making R2 the subject of the formula on the following Wiki page, it's the one under Applications - Voltage Source (Vout = ...)? I don't know how to include the formula on here. Sorry !
Link to page - Voltage divider - Wikipedia, the free encyclopedia